Numerical Simulation of Inertial Based PDMS Microchannel for Blood Cell Sorting

Inertial focusing of particles in curved channels has much potential for lab-on-a-chip applications. For high-throughput cell sorting, inertial microfluidic channels with a spiral cross-section have been used, using the vortex assumption of two opposing Dean vortices. Using the Navier-Stokes equation as a basis, this investigation employs a numerical simulation of the flow dynamics to examine the trajectories of particles and the fluid velocity profile in the curved channels. Variations in flow rate, Reynolds number, and particle size are examined to see how they affect the performance of the focusing forces and the competition between them. Human blood has three main cell types: red blood cells (RBCs), white blood cells (WBCs), and platelets. By adjusting the flow rate and maintaining it along the spiral microchannel, these cells of sizes (15 μm, 6 μm and 2 μm) are separated more effectively. The high flow rate of about 4.5 mL/min is achieved for the planned 6 turn spiral microcfluidic device to reach its maximum separation efficiency. This work reimagines the role of Dean flows in cell focusing at high flow rates, which may one day allow for more effective separations of blood cells at ultra-high throughputs.